I don't know that this will help, but, are you SURE that's a goldfinch? The gold is darker than the males here, the wing and tail feathers have more black and less grey. That little critter is also downier than the finches I've seen, and has way too sardonic an expression for a finch. Of course, it may have been attacked by a cat or a hawk or something, which would make anyone sardonic and ruffled.

Looks more like a Pine Warbler than a female Goldfinch.

The ASPCA and Humane Society are good ideas, but I doubt they deal with songbirds. Try the local Co-operative Extension office. What happens when the bird tries to fly?